Record on Nematode Tanqua tiara Infection on Snakehead Fish Channa striata in South Kalimantan Indonesia

Highlight Research The parasitic disease has been record in snakehead fish (Channa striata) from South Kalimantan The nematodes with needle shape on both tip end with approximately 1 mm length and moving inside of wall cysts were found in in abdomen cavity and flesh of fish The morphology of the nematode was observed by light- and scanning electron-microscope The analysis on 18S rRNA showed that this parasite is belonging to nematode Tanqua tiara   Abstract Snakehead fish (Channa striata) is an important commodity in South Kalimantan Indonesia. The snakehead fish production was increased due to the capture and intensive culture. The disease is one of the obstacles for production that may happened in cultured- and wild-fishes. The aims of this study were to record and to identify parasite which infected on wild snakehead fish from Kandangan Lama, Panyipatan, Tanahlaut, South Kalimantan. The parasite identification was conducted based on the morphology and the molecular characters. The morphology was observed by light microscope and scanning electron microscope. The 18S rRNA of parasite was amplified using designed primers and followed by sequencing. Spherical cysts were found in abdomen cavity and flesh of snakehead fish. The cylindrical worm with needle shape on both tip end with approximately 1 mm length were moving inside of wall cysts. Alignment analysis of 18S rRNA showed the highest homology at 99.83% with Tanqua tiara. Phylogenic tree showed that this worm is located at distance clade with the nematodes that have been reported to infect snakehead fish. The morphology and molecular results verified that and first report the parasite found in snakehead fish in South Kalimantan was T. tiara species. This nematode parasite may be served as intermediate host.